Discussing this with another interested party we came to the conclusion that the HC codes were the wholesalers own codes starting with the supplier Hudswell Clarke and indeed were a comparison with the Feuerhand equivalents. ( Perhaps a range that the reps were already familiar with. ) The P35 designation appears to be the manufactures code and may have applied to the entire range of lanterns. Then they could have been differentiated by the height as they are on the wholesale catalog page. Something like P35/10” P35/12” & P35/14” It does seem to fit the available information. I think this will be what I will use in my own notes until I know any better.
